A sensor network that collects sensing data acquired by a sensor node as an event is known. A variety of services that include emitting an alert or controlling a device is provided in response to an event acquired by a server node via the sensor network.
If the server node collects events from sensor nodes, all the events converge on the server node when they are notified. As a result, the load on the server node increases, and network bandwidth becomes tight as traffic on the network increases.
Techniques that have been disclosed control the load of a server node and network traffic. A system disclosed as one of the techniques improves system performance and/or resource consumption by transferring a filter agent that filters data from a consumption node to a data generation node. Another disclosed technique relates to a sensor network system that uses a script with a nested structure, and causes an intermediate node or a lower node to execute part of the script.
The above-described techniques are disclosed in Japanese Laid-open Patent Publication Nos. 2008-97603 and 2006-344017.